The TAC5 advanced airflow control technology is the result of a development and an experience over more than 20 years.

TAC means « Total Airflow Control »,TAC controller makes possible to control with high precision the operation point of our fans equipped with DC motors. It is therefore possible to know in real time the airflow and the pressure and to fix one of these 2 parameters as an instructed to maintain constant.

This is based on a series of calculations algorithms developed and improved over the years by our Lemmens research & development department.

4 operating modes are available :

  • Constant airflow (CA mode)is used when one or several stable air volumes are needed. The fan will deliver the requested airflow regardless of the pressure conditions. This is the simplest mode; it allows for three different pre-set airflows (low, medium, high) and is used with simple control. For Eco units equipped with backwards curved blades, the kit CA composed of a pressure sensor is needed to use this mode.

  • Constant torque mode (TQ mode) : This mode simulates the ‘normal’ operating mode for the fan when using a frequency controller or a transformer. The fan torque is modulated instead of the airflow. The mode allows to preset three different ‘percentages’ of the maximum fan torque. This mode is available for ECO units with plug fans when constant airflow is not required.

  • Variable constant airflow (LS mode)) In this case, the constant airflow requested is linked to a 0-10 V signal. Measuring the CO2 level, for example. When the level is high (many people present), the airflow rate will be adjusted accordingly, and vice-versa when there are few people in the room. Energy consumption will follow the real ventilation requirement.

  • Constant pressure (CP mode): ): With this mode, a variable flow rate is used to maintain a constant pressure. A particularly interesting application of this operating mode is undoubtedly the individualized ventilation of apartments by a centralized ventilation unit. Once configured, the ventilation of each apartment remains constant even if several apartments change their ventilation demand because the pressure in the network is constantly maintained. A pressure measurement sensor is used to configure this very useful mode.

According to the type of TAC 5 controller used, part or all of the following features specific to TAC5 are available:

  • BOOST - A large airflow is used when the ventilation requirement increases, e.g. for cooking,taking a sauna,showering and drying laundry.

  • Time table  You can switch as required to an appropriate operating mode or let the preprogrammed weekly clock switch operating mode according to the diurnal rhythm you want..

  • Opening – closing of the motorized dampers 

  • Constant pressure (CPs), maintains a constant pressure in the duct measured by a sensor.. One application of this can be for example VAV systems (variable air volume).

  • Power control of the electrical coil, cold water/ hot water coil, in order to maintain a constant supply temperature or a constant room temperature.

  • Anti-frost protection of the water coils.

  • Free cooling cooling automatic free cooling of the building during summer nights, (Open/closed bypass of the heat exchanger in order to generate the cooling of the indoor air of the building by supplying direct fresh outside air. The opening may be all or nothing or modulating to control the supply air temperature.

  • Anti-freeze protection protection of the heat exchanger. 3 types of solutions are available: unbalanced airflow (reduced supply air flow), regulating the power of a preheating battery (electric or water), modulating the opening of the bypass.

  • Enslavement of the airflow instructions to 2 sensors simultaneously (CO2 / VOC and HR).

  • Up to 74 types of alarms available generates a clear and precise diagnosis in case of failure of a component or a too high pressure in the ducting system.

TAC 5 controller makes also available a wide range of user interfaces or interaction with other building techniques :

  • T4 types de communication sont disponibles :

    • WIFI
    • KNX

    They allow different TAC units to interface with each other, but also to integrate them easily into a centralized building management system (BMS) in charge of the management and supervision of all technical parameters of the building (ventilation, heating, conditioning, lighting, security, access, ...).

  • A wide selection of user interfaces :

    • LCD screen  on the control board.

    • RC Remote control box that includes an LCD screen.

    • GRC Graphic remote control with a color touchscreen which can be connected to several units.

    • APP for PC..

    • APP for IOS and Android Free user-friendly dedicated Lemmens APP for tablet and smartphone.

    • KNX  for a communication with any KNX display or interface.